Need some help with an exponent simplification questions

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SUMMARY

The discussion centers on simplifying the expression \(\left(\frac{1}{n}- \frac{2}{n}\right)^2\) and identifying errors in the simplification process. The user incorrectly equated \(\left(\frac{n-2n^2}{n^3}\right)^2\) to \(\frac{n^2-4n^4}{n^6}\) without applying the correct formula for the square of a binomial, which is \(a^2 - 2ab + b^2\). The correct approach involves recognizing the least common denominator as \(n^2\) and ensuring all terms are accounted for in the expansion.

PREREQUISITES
  • Understanding of exponent rules and simplification techniques
  • Familiarity with binomial expansion, specifically the formula \(a^2 - 2ab + b^2\)
  • Knowledge of fractions and least common denominators
  • Basic algebraic manipulation skills
NEXT STEPS
  • Study binomial expansion in detail, focusing on the formula \(a^2 - 2ab + b^2\)
  • Practice simplifying expressions with positive exponents
  • Learn about least common denominators and their application in algebra
  • Review common mistakes in algebraic simplifications to avoid similar errors
USEFUL FOR

Students studying algebra, particularly those struggling with exponent simplification and binomial expressions, as well as educators looking for examples of common mistakes in algebraic manipulation.

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Homework Statement



express the given expression in simplest form with only possitive exponents


Homework Equations



**refer to attached drawing**


The Attempt at a Solution



Refer to attached drawing to see my attempt and to see what the real answer is. I don't understand where i went wrong in my steps, in the final answer there is a (-4n) i don't know where that came from.

Greatly appreciated if one of you smart guys could lend us a hand. Thank you.
 

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you have
[tex]\left(\frac{1}{n}- \frac{2}{n}\right)^2[/tex]
and say that is equal to
[tex]\left(\frac{n-2n^2}{n^3}\right)^2[/tex]
While they are equal, the LEAST common denominator is n2, not n3. You do, in fact, eventually cancel the spare "n"s so that is not the problem.

The real problem is that you have
[tex]\left(\frac{n- 2n^2}{n^3}\right)^2[/tex]
and say that is equal to
[tex]\frac{n^2- 4n^4}{n^6}[/tex]
That is incorrect: (a- b)2 is NOT a2- b2!
It is a2- 2ab+ b2. You forgot the "middle term".
 
thanks

Thanks a lot HallsofIvy, i appreciate your help mate.

It was such an obvious solution i can't believe i didnt figure it out myself.

Why does this happen sometimes?, the answer is right in front of you but a person still fails to see it?

I think i must be tired from work that is why. Or mybe i am craming in too much maths information into my brain in such a short period of time.

Anyway...thanks again.
 

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